Put on Dr. John's 1968 debut, Gris-Gris, and no matter where you are, it becomes nighttime on a lonely bayou and you are the unwelcome, painfully out-of-place tourist. Every living thing is moving stealthily and slowly. Along comes a croaky old critter, snake-oil-selling the power of his gris-gris, talking about the way he gonna make somebody pay, the damage he can do with dust and potions and the mists of the swamp night. "Put gris-gris on your doorstep/Soon you'll be in the gutter," he sings. "Melt you like butter/I can make you stutter."

Gris-Gris is the New Orleans appropriation of California psychedelia, dressed up in Mardi Gras finery and spiced like a gut-busting gumbo. Pianist Mac Rebennack, who created the character Dr. John while working as a session keyboardist in Los Angeles, ran it down just right: Casting himself as an all-seeing brujo equipped with cures for common ailments and metaphysical quandaries, he became a Cajun Captain Trips, a flamboyant ringmaster who dispensed advice and cutthroat commentary with a pinch of French Quarter mumbo jumbo.

Gris-Gris, which was produced by the pianist Harold Battiste and features many of New Orleans' finest, is a spacey glass-bottom-boat tour of the myths and legends of the city's midnight realm. Though Dr. John later established himself as a persuasive interpreter of New Orleans R&B — the music of the Meters, Professor Longhair and James Booker — at this point he was more of a raconteur, calling out the local characters ("Mama Roux" is immortalized in an Afro-Cuban pulse) and those affiliated with the secret societies, unspooling fragmented tales over droning, repetitive, intoxicating vamps.

Of these, the album-closing "I Walk on Gilded Splinters" endures as a classic — a masterpiece of vibe that has retained its aura even after being sampled and covered every which way. An ambling processional framed by a simple pentatonic guitar melody, it's everything you want in voodoo music: a feast of pummeling drums, swirling ethereal voices and the patient, mumbled incantations of Dr. John, all coalescing into the sound of a solemn, revelatory ritual.